appview: assortment of fixes

- allow repo website to be empty when editing base settings
- fix spindle hostname in nix vim
- fix default PLC url in spindles

Signed-off-by: oppiliappan <[e-mail]>

appview/repo/settings.go

···
 	)
 
 	err = rp.validator.ValidateURI(website)
-	if err != nil {
+	if website != "" && err != nil {
 		l.Error("invalid uri", "err", err)
 		rp.pages.Notice(w, noticeId, err.Error())
 		return

nix/vm.nix

···
           enable = true;
           server = {
             owner = envVar "TANGLED_VM_SPINDLE_OWNER";
-            hostname = envVarOr "TANGLED_VM_SPINDLE_OWNER" "localhost:6555";
+            hostname = envVarOr "TANGLED_VM_SPINDLE_HOST" "localhost:6555";
             plcUrl = plcUrl;
             jetstreamEndpoint = jetstream;
             listenAddr = "0.0.0.0:6555";

spindle/config/config.go

···
 	DBPath            string  `env:"DB_PATH, default=spindle.db"`
 	Hostname          string  `env:"HOSTNAME, required"`
 	JetstreamEndpoint string  `env:"JETSTREAM_ENDPOINT, default=wss://jetstream1.us-west.bsky.network/subscribe"`
-	PlcUrl            string  `env:"PLC_URL, default=plc.directory"`
+	PlcUrl            string  `env:"PLC_URL, default=https://plc.directory"`
 	Dev               bool    `env:"DEV, default=false"`
 	Owner             string  `env:"OWNER, required"`
 	Secrets           Secrets `env:",prefix=SECRETS_"`